Cisco WS-C3560-48PS-S Software Configuration Manual page 739

Chapter 32 Configuring IP Multicast Routing
Configuring Advanced DVMRP Interoperability Features
Figure 32-6 Leaf Nonpruning DVMRP Neighbor
Source router or RP
RP
PIM dense mode
Router A
Valid
Router B
multicast
Receiver
traffic
Layer 3 switch
Unnecessary
multicast
traffic
Leaf nonpruning
DVMRP device
Stub LAN with no members
You can prevent the switch from peering (communicating) with a DVMRP neighbor if that neighbor does
not support DVMRP pruning or grafting. To do so, configure the switch (which is a neighbor to the leaf,
nonpruning DVMRP machine) with the ip dvmrp reject-non-pruners interface configuration command
on the interface connected to the nonpruning machine as shown in Figure 32-7. In this case, when the
switch receives DVMRP probe or report message without the prune-capable flag set, the switch logs a
syslog message and discards the message.
Catalyst 3560 Switch Software Configuration Guide
32-43
78-16156-01